Apparatus for roasting or sintering ores



J. E. GREENAWALT.

APPARATUS FOR ROASTING 0R SINTERING ORES.

` APPLICATION FILED Nov, Is. I9IoA fw?, Patented Aug. 39 i920,

3 SHEETS-SHEET l.

I. E. GREENAWALT. v APPARATUS FOR HoAsTING 0H sINIEmNG DRES. APPLICATIONFILED NOV-.118, 19104 .l SA?. A Patented Aug. 3, 1920.

3 SHEETS-SHEET 2.A

f .MWM/ l J. E. GHEENAWALT.

APPARATUS FOR ROASTING-OR SINTERING ORES.

APPLICATION FILED Nov,1a. I9Io.

, l 348,40?" I, patented Aug. 3, 1920.,

3 sHEETs*sI-IEET 3. w

s; y/ IH..

@Hemmum f/,QZQWW 'll'OHN'` E; GREENAWALT, 0F DENVER, COLORADO.

astiene?.

'-To all whom t may concern:

Y Be it known that I, J oHN E. GREENAWALT,

4 a citizen of the United States, residing at Denver, in the county ofDenver and State of'Colorado', have invented certain new and usefulImprovements in Apparatus for- Vlbioasting or Sintering Orcs; and l vdodeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which'- itappertains to' make and use the same,

reference-being had to the accompanying` drawings, and to the charactersof reference marked thereon, which form a part of this specification.

My invention relates to animproved apparatus for roasting ores andespecially for desulfurizing and agglomerating or sintering thepulverized ore preparatory to smelting.k The apparatus may also beemployed to treat ore with any suitable gas, as chlorin,

for instance, wherev the object is to chlo-vridize part or all of themetals contained in the charge; For example, this apparatus isespecially designed and constructed to utilize the downdraft process oftreating ore and other material set forth in Letters `lPatent- No.839,065, issued to me December The special object to be attained byV mypresent invention in connection with the process protected by theaforesaidl patent, is a simple and economical agglomeration of linematerial and at the sametime desulfurizing it sufliciently for smeltingpurposes.

The operation is intermittent and based' upon the principle of passingthe air or other gases downwardly through the ore mass and its poroussupport, as a grate, and thence through the exhauster or suctionproducing apparatus. When this use is made of the apparatus the chargeshould contain sufficient combustible material to maintain the,l propertemperature to secure the results deslred. In sintering ores, for examle, it

is desirable to have 'at least 10% sul ur in.

the charge, which with, 'the proper amount of air passing through themass will produce sufficient heat to agglomerate the same.

In myexperience, fty cubic feet of air per.

minute for each square foot of grate area gives excellent results. Theshould be capable of givingat least 12 to 16 ounces 'of suction orvacuum" pull; ln the operation of the plant, the charge properlymoistened and thoroughly mixed, is

Specification of Letters Patent.

exhauster IABAJFUS,v FOR ROASTING OR SINTRING GRES.

Patented Aug. 3, 192th Application led November 18, 1910. Serial No.592,997.

placedI upon a porous layer or bed a roasting pot or pan, this porousbed in turn' in the charge. ln lieu of oil,"ll may employ' gasolene,powdered `carbonaceousy fuel, or

any suitable gaseous fluid for the purpose of igniting the charge. f

A complete plant for practising my invention may consist of a box-likecast iron roasting pot or equivalent open top ore holder mounted ontrunnions, one of which is hollow, through which the gases andcornbustion products are drawn into the exhausting apparatus.' Aportable igniter is mounted so as to be removed from the pot during theoperation of filling and discharging the latter. This igniter consistsof a hood or cover shaped to harmonize with the top of the pot andfitting closely thereon when lowered into position. The igniter` may besuspended to travel over -an area occupied by 'a series of pots, sinceone `igniter may be employed in connection with suitable openings areformed "in the cover to allow the necessary air to enter for pur-v 1poses of combustion. This oil is delivered to the atomizers underpressure, preferably of about sixty. (60) pounds per square inch.

ence, as soon as the oil Vis turned on, the chamber of the igniter abovethe charge is instantly filledY with atomized oil sprayed into saidchamber by the nozzles aforesaid. In this form the oil is readilyignited, the burning particles fillin the chamber with flame, and inabout hal a minute the` entire surfaceof the charge is in anincandescent state, caused by the flame being brou ht into intimatecontact with the charge. he

.products of combustion escape through the hollow trunnion of the pot.After the charge is sintered the pot is revolved o n its trunnions andthrown to an inverted posltion, when the sintered massor cake fallsoutand passes downwardly striking upon an inclined chute which is equippedwith angle iron members adaptedto break up `the mass, which is renderedporous and Ab rittle by the sintering operation. This angle iron chuteserves to breakup the ore'to a considerable extent, but the largerpieces may be further broken by sledging or in any other suitablemanner, so that the sintered product may pass throughf suitableOpenings` at the bottom of the chute, through which it drops toreceiving cars.

Havin briey outlined my im roved constructlon, l will proceed todescribe the same in detail, reference beingi made to the accompanyingdrawing in which is illustrated an embodiment thereof.

. ln this drawing:

Figure 1 is a vertical section taken upright framework upon which issupfy ported, some distance from tthe bottom, a

sintering pot 6 divided into up r and4 lower 4chambers or compartmentsgg respectively by a grate or perforate member^9 carrying a porous layer10 forming aand 8 pervious support upon which rests a charge 12 ofpulverlzed ore to be si'ntered. This I. pot has a surrounding top rim oryflange 13 upon which the lower flanged edge 14 ofa cover or hood 15 isadapted to t. This cover is formed hollow and of considerable depthwhereby 'a mixing and ignition cham,-

ber 16 is formed, making it practicable to mingle the necessary fuel oilwith air for purposes of combustion, the oil entering 1 livered into thetop the mixing chamber of the i niter through spray nozzles or burnersl? and the .air through'narrow .slots or openings 18 formed in the topof the cover. As illustrated in the drawing anumber of nozzles 17 extendfrom vtransverse pipe sections 19 located at 1 each end of the cover andare in communication ywith a central longitudinall disposed pipe 20 towhich leads a lexib e, conduit 21 from an' oil tank 22 in whichrthe oilis maintained under pressure by air dev of the tank above the level 23of the liquid through the agency of a pipe-24` connected with anairco'mpressor )25. 'lheiconduit 21 contains a l controlling extendinwardly and slightly into .the cham' ber 16 through openings 4 formednear the top of thesides of the cover, the nozzles, on one side beingdisposed substantially diametrically opposite the corresponding nozzleson the opposite side.

The igniting cover 15l is eqpipped at each extremity with a bail 27. eupper extremity of each of these bails is plvotally connected, as shownyat 28,'with a hand lever 29 fulcrumed at 30 on a carriage 31 composed ofend frames 32 connected byfrods 33 and 34 and carrying wheels35 enga 'ngthe base ilanges 36 on opposite sides4 o an eye beam 37 secured to thetop of the frame. Each of these hand levers 29 is provided at itsextremity opposite from the pivot 28 with a chain 38 whose links areadapted to engage aV hook`39 formed on the top of the Acover 175. ltwill thus be observed that the cover may be raised and lowered byutiliz-V ing the chain extremities of these levers, the chainscoperating with the hooks to which they may be readily attached and fromwhich they may be readily'detached,

I as circumstances may require.

Where the igniter is used in'connection with a number of pots 6 asillustrated in* Fig. 3, the flexible conduit 21 must be long enough topermit the necessary travel in going from the pot at one extremityv ofthe series to the other. 1n this event the oil tank 22 should,ofcourse,l be centrally lov cated (see Fig. 3)', and it may be assumedthat the line of pots 6 in this view is extended in both directionsuntil say ten or a` dozen pots are arranged in a line, the charges ofall of which may be ignited by the useA 4of a single portable ignitinglapparatus ofthe character illustrated and' described herein.

Each pot6 is trunnioned at its extremities as shown at 40 and 41. Thetrunnion 41 is hollow and a tight joint is formed around the same by theemployment ofa sort of stuiling box 42. The opening 43 through thistrunnion communicates with the air and .gas

compartment or chamber 8 ofthe pot below the grate and also with achamber 44 inclosed by a housing 45 from which a duct or ris downconduit 46 leads to an exhauster 47 operated from a motor 48 through theagency of a belt 49. vA belt 50 alsoleads from the motor tothe aircompressor 25 (see Fig. 1). When the igniter is used in connection withanyA pot, the chamber 7 of the latter having been first charged withore, the cover 15-'is dropped downtoengagement with the rim of thepotwith which it forms a sealor 'air-and-gas Atight joint. 4Theoil is thenturnedon by opening the valve 26, causing the oll by virtue `ofthe'pressure from the tank 22 to be forced through the nozzles 17 andthence into` the chamber 16 of the igniting cover, vwith suilicientforce for atomizing purposes. rllhe atomized oil islthen ignited,

filling the ignition chamber 16 with flame,

and the suctlon apparatus or exhauster being in operation, the flamesand hot combustion products from the burning oil are drawn downwardlythrough the open bottom of the chamberinto the pervious layer or chargeof ore, the operation being continued until the combustible material,principally sulfur, of the ore is thoroughly ignited. The oil isthen'turned olf by the closing of the valve 26., and, if desired, thecover may be lifted sufficiently to clear the pot, after which the coveris moved along upon its carriage out of the way or to the next pot,where a series of pots is employed, the same operation being repeatedwith each pot.- The ore charge Ahaving been ignited by the temporaryapplication thereto of the dames and combustion` products as abovedescribed, the combustible material in the ore will thereafter maintainthe combustion, furnishing the necessary until its position-is reversed,its top being down as indicated by dotted lines in Figs 1. y'

The charge will then fall out and pass downwardly striking upon aninclined chute 51 where it engages the upwardly projecting flanges 52 ofa series of angle irons 53 which 'breaks it up to a considerable extent.rlhe ore then moves downwardly on the chute to openings 54 formed at thelower extremity thereof through which it passes.' lf any chunks orpieces are too large to pass through these openings into the cars 55below, they may be further broken by sledging as heretofore stated.

An important object snbserved by the cover or hood 15 is that whendepositedover the pot or receptacle 6, and the fuel is turned on, theigniting flames in .response to the suction of the exhauster, are 'drawnagainst the sur` face of the chargeof ore, and the entire surface ofsuch charge is simultaneously ignited. This simultaneous ignition of theentire orecharge surface is one of the indispensable features of thepresent invention, enabling as it does the zone of combustion toprogress evenly through the entire ore charge without danger ofbecominglocalized or having its action confined to restricted areas.practice the dimensions of the pot 6 are approximately six by eight feetand in some instances the size of the potV is even greater. It isindispensable therefore, with a pot having so extended an area, that theentire surface of its charge shall undergo simultaneous, thoroughandcomplete ignition so thata corresponding roasting, or sintering actionmayollow. I

Having now described my invention, what lclaim is:

1M. 'ln combination with an open top holder for a charge of material tobe treated, an

.igniting member movable relativelyto said holder and.. adapted to betemporarily positioned overl the holder and its charge 1n non-- movablerelation thereto, and operating to ignite the charge at its surfacewhile so positioned. f

2.- In combination with an open top holder for acharge of material toybe treated, a

' flame-confining hood adapted` to be superposed over the, holder and.its charge-'for igniting the charge at its'surface.

3. In combination with anl open .atop

holder for a charge of material to betieat' ed, an igniting cover orhood adapted to be positioned overl the holder andits chargel andoperating to ignite the charge at its surface when so positioned.

4. ln combination with an open -top holder for a charge of material tobe treated, an igniting cover or hood' adapted to be temporarilypositioned over the holder and its charge and operating to ignite thecharge at its surface while so positioned.

5. In combination with an open top f holder for a charge ofmaterial tobe treated,

a lame-conining igniting cover or hood adapted to be positioned over theholder and its charge and operating to ignite the charge at its surfacewhen so positioned.

6. lin combination' with `an open. top

holder for a charge of material to be treated,

a flame-confining igniting coverory hood adapted to 'be temporarilypositioned over the holder and its charge and operating `to ignite thecharge atv its surface while so positioned.

7. ln combination with an open top holder for a chargeof material to betreated,

a portable igniting cover or hood adapted to be positioned over thecharge and operating to ignite the charge at itssurface when sopositioned.

8.111 combination with an open top holder for a charge of material to betreated,

la portable igniting cover or hood ada ted to be positioned over thecharge` and orm above the charge a suitable ignition chamber, and meansyfor delivering to said chamber `fuel in suitable form for igniting thecharge lrat its surface.

9. ln combination with a pan adapted to receive a charge of material tobe treated, a portable hood adapted to be applied to the top ofthe pan,and equipped with means for feeding fuel in duent form above `the chargefor igniting the charge at its surface.

not

are

vao

. 10. ln combination with a plurality of separated pans arranged insuitable proximity to one another and respectively adapted to receivecharges of material to be treated,

a portable igniter comprising a coverfor closing the top of any pan andform an ignition chamber abovel the charge in said pan, and providedwith meansfor feeding `fuel in fluent form' into'` said chamber, the

agglomerating or sintering operation, and.

means for igniting the material at its surface by causlng flamingparticles and highly heated products of combustion to be temporarilypassed into said chamber.

12. An apparatus for agglomeratingv or sintering ore, comprising apervious support for a thin bed of ore, a chamber having perforate`Walls surmounting the support and its charge, meansfor causing asupporter of combustion to pass into said chamber through the wallsthereof, thence through the ore and its support throughout the entireagglomerating or sintering operation, and means for igniting thematerial by causing aming particles and highly heated products ofcombustion to be temporarily `maintained in said chamber in contact withthe surface of the supported bed of ore.`

' 13. ln an apparatus for agglomerating or sintering ore, thecombination of a perfof rated support` for a` pervious bed of ore, meansfor causing' a supporter of combusI tion to pass through the ore bed andits'sup# port throughout the entire agglomerating or sinteringoperation, and an igniter covering but spaced from the charge, providedwith a uid hydrocarbon burner arranged to temporarily project a broadand intense mass of flaming particles into the space above the surfaceof the ore, which are drawn into intimate contact with the area of saidsurface by the supporter of combustion caused to pass throu h the orebed.

14a. 1n an apparatus or agglomerating or sintering ore, the combinationof a perforated support for a pervious bed of ore, means for causing asupporter of combustion to pass through the ore bed and itssupportthroughout the entire agglomerating or sintermg operation, and anigniter having perforated walls covering but spaced from the charge,provided with a fluid hydrocarbon burner arranged to temporarily projecta broad and intense mass of flaming particles into the Space .above thesurface of the Lemgo? ore, which are drawn into intimate contact withthe area of said surface by the supporter of combustion caused to passthrough the ore bed.

15. In an apparatus for agglomerating or sintering ore, the combinationof a perforate supportfor a thin bed of ore, means for causing asupporter of combustion to pass through the ore throughout the entireagglomerating or sintering operation, an tion chamber above the charge,and a palr of spray burners carried by the Walls of the said chamber atpoints substantially da? metrically opposite each other near theopposite edges of the supported bed of ore.

16. In an apparatus for agglomerating or sintering ore, the combinationof a perforate support for a thin bed of ore, means for causing asupporter of combustion to pass through the ore throughout the entireagglomerating or .sintering operation,.an igniter having perforate Wallscovering but spaced from the charge and forming a mixburners on theigniter for temporarily projecting into said mixing chamber a broad andintense mass of flaming particles for igniting the ore at its surface. jl

17. ln an apparatus for agglomerating or sintering ore, a'perforatesupport for a thin bed of ore," an igniting hood for covering yandsettingre to the ore While upon the support, and means for causingcurrents of air or other supporter of combustion to pass through the ore-While covered by the hood. 4 f f 18. In an apparatus for agglomeratingor sintering ore, a perforate support for a thin bed of ore, an ignitinghood havin perforyateWalls for covering and setting re to the ore whileupon the support, and means for causing currents of air or othersupporter of l ing chamber above the charge, and spray combustion topass through the perforations in the walls of the hood and through theore VWhile covered by the hood.

19.' In an apparatus for agglomerating or sintering ore, a perforatesupport fora thin bed of ore, an igniting hood for covering and settingfire to the ore'while upon the support,

said hood having perforate walls spaced from the` surface of the orecharge, an air compartment arranged below said support, and means forcausing a supporter of combustion to enter the hood through theperforated walls 'thereof and pass thence through the ore and into thecompartment below the ore support, and theny out of said compartment. fy

20. In an apparatus for agglomerating or sintering ore, the combinationof a perforate support for a' thin bed ofore, an igniting hood for'covering and setting tire to the ore while upon the support, said hoodvbeing provided with a mixing chamber, means for feeding into said.chamber suitable ignition retener fuel, means for causing asupporter ofcombustion to enter the mixing chamber to maintain combustion therein,and means for causing the gases to pass through the ore and through theperforate support.

2l. ln anapparatus for `agglomerating or sintering ore, the combinationof a perforate support for the ore, a lame-coniinmg igniting hood forcovering the ore while upon the support and directing the hot productsof combustion into intimate contact with the surface of the ore to beignited, and means for causing currents of a gaseous supporter ofcombustion to pass through the ore While covered by the hood.

22. In an apparatus for agglomerating or sintering ore, a perforatesupport for a thin bed of ore, an igniting flame-confining hood forcovering the ore and Setting `.fire t0 the ore at its surface While uponthe support,y means for cutting off the igniting flame, and

means for causing combustionof the ore to be continued after theigniting flame has been cut 0H'.

2:5. ln an apparatus for agglomerating o r sintering ore, a perforatesupport for the ore, and an igniting hood for covering, vand settingfire to the ore at its surface whil upon the support.

24. In an apparatus for agglomerating or sintering ore, a suitableholder, a perforate support for the ore in said holder, and an ignitinghood for covering and lsetting lire to the ore at its surface While uponthe support, the hood forming with the surfacey of the ore'chargeasuitable mixing chamber, and means for admitting air or other supporterof combustion to said mixing-chamber.

25. In an apparatus for agglomerating or sintering ore, a pervioussupport for the ore, and a flame-confining igniting hood for covering,and setting fire tothe ore at its surface while upon the support.

26. In an apparatus for sintering ore, the combination with means forholding a body of ore disposed in a layer, of an, igniting hood or coverfor the ore having a chamber with an open bottom and arranged to confinehot igniting materials and direct the heat therefrom to an area of theore mass corresponding With the area of the open bottom of the chamber.

27. ln an apparatus ntorv agglomeratln and sintering ore, a support forapervious bed of ore, means for causing a supporter of combustion to passthrough the ore, and an igniting hood or cover provided with a chamberin which is temporarily maintained a supply of products of combustionheatedl to an ore-igniting temperature and directed against the surfaceof the ore exposed to said chamber. -K

28. In an apparatus for` forming cakes of agglomerated or sinteredorefrom a mass initially containing a metal-bearing material inpulverized form and also a combustible ingredient, the combination of aholderadapted to have disposed therein a relatively thin. layer of saidmass and having a perforate support on which the mass rests, the

walls of the holder surrounding the saidk mass, an igniting covermovable relatively to the holder for setting ire to the ore at itssurface, and means for causing combustionsupporting gas to pass throughthe said layer, the holder being tiltable to permit (.lischarge of thesinter upon removal of the igniting cover.

29. ln an apparatus for'lforming cakes of the ore mass and formafrnixinfr chamber above the surface of the ore, and means for causingcombustion-supporting gas to ypass through the Walls of the cover, intothe mix-A ing chamber and through the said layer and its support, thefinished sinter being free to discharge upon a removal of the cover andtilting of the holder. a

30. ln an apparatus of the class described, the combination of a panadapted to receive a charge of ore or other material to be treated, aportable hood adapted to fit the top of the pan and equipped withnozzles at each 'end thereof for delivering fuel in fluid form tofthecharge, the bottom of the pan having openings, and means connected withthe bottom of the pan for exhausting the products'of combustion bydrawing them down through the charge and out through the bottom ot theforth.

31. The combination of a pan Whose bottom forms a support for the chargeto be treated, an igniter comprising a hollow cover adapted to fit thetop of the pan and forming a chamber above the same for mixing air withfuel in fluid form, the cover being equipped with nozzles located ateach end thereof for feeding the vfuel to the mixing` pan, for thepurpose setice lll@

each an and equipped with means for feeding el to the charge in fluidform, the igniter being supported totravel from one pan to another, forsuccessively igniting the charges of the several pans.

33. ln combination with areceptacle having a support for the charge,said support having openings for they traverse of gases from the charge,an exhauster, means responsive to the action of the exhauster foreecting a simultaneous ignition of the chargethroughout the entiresurface thereof, and means for excluding crossv air currents from thecharge therebyproducing a zone of combustion progressing uniformlythroughout, and coextensive with, the charge. f

by means of an overhead carriage to travel` from one pan to the otherfor successively` igniting the charges of theseveral pans,'sub

stantially as described.

35. ln combinationl with areceptacle having a support for the charge,said support having passages for the' traverse of gases from the charge,and aliigniting hood coextensive with the area of the charge posiv withmeans comprising nozzles located lat 'titl tioned over the receptacleand making a seal with the walls thereof against influx of crossatmospheric currents into the bottom of the hood, whereby a zone 'ofcombustion uniformly and simultaneously permeating the entire charge, ismaintained.

36. rl`he combination of a pan adapted to receive a charge of materialto be treated, the pan being trunnioned for dumping purposes, and aportable igniter adapted to-be applied to the top of the pan andequipped each end thereof, for feeding fuel thereto in fluid form, theigniter being movable away from the pan to allow the latter to turn onits trunnions for dumping purposes, substantially as described.

37. rlhe combination of a pan provided' with a support for the charge-tobe treated, the support having an opening therein, means for exhaustingthe products of coinbustion by drawing them down through the .thecombination of a pan adapted to receive a charge of ore or othermaterial to be treated, the pan being equipped with a supan and equippedport for the charge, the support having an opening therein, a portablehood adapted to fit the top of the pan and equipped with nozzles at eachend thereof for delivering fuel in fluid form and under pressure to thecharge, and means connected with the pan for exhausting the products ofcombustion by drawing them down through the charge and its support, forthe purpose set forth.

39. A sintering apparatus, comprising a receptacle rotatable about afixed axis and having an upper compartment for the charge and acompartment below the chargey communicating with the upper compartmentthrough the charge and its support, a'hollow .trunnion leading from thelower compart ment and disposed about the rotation axis of thereceptacle, an exhauster couple'd to the trunnion, a hood or coveradapted to'be temporarily placed over the charge,A and means on saidhood for supplying anfiniammable mixture adapted to be drawn, toward thesurface of the charge whereby the entire area of said surface may besim'ul taneously ignited. y Y

4:0. A sintering apparatus comprising a receptacle having a perforatedmember for the support of the charge, an exhauster for drafting gasesdownward through the charge and through said perforated member, a hoodadapted to betemporarily positioned over the receptacle and charge, andmeans on said hood for delivering fuel and air over the charge wherebythe ignition gases are draft- -edover the surface of the charge and thelatter is ignited simultaneously `substantially throughout its entirearea', the hood making an air-tight joint with the walls of thereceptacle whereby cross air currents are excluded and the zone ofcombustion is caused to permeate the entire charge.

41. A sintering apparatus comprising a receptacle having a perforatedsupport for the charge, an exhauster for drafting gases downward throughsaid charge and through said support, a hood adapted to be tempo-'rarily positioned over the receptacle and form a combustion chamberabove the charge, sealed at the bottom against access of atmosphericcross currents, and means for filling said chamber with inflammablevmaterial whereby the entire surface of the charge is -simultaneouslyignited and the gases drawn through the entire charge, and whereby thezone of combustion uniformly permeates the entire charge.

42. A sintering apparatus comprising a p tilting receptacle have aperforated support for the charge, an exhauster for drafting gasesdownward through the charge and its support, a removable hoodtemporarily deposited on the receptacle and forming a combustion chamberabove the charge sealed at the bottom against access of atmosphericcross-currents, and means carried by the nsaaaoa hood for filling saidchamber wi th igniting gases whereby the entire surface of the charge issimultaneously ignited and the roaster gases are drawn evenly throughthe charge toward the exhauster, the seal aforesaid preserving theintegrity of the zone of combustion throughout the entire charge.

43. ln an apparatus for agglomerating or sintering ore, a perforatesupport for a thin bed of ore, a hood for covering practically air-tightthe ore while upon the support, means for causing a supporter ofcombustion to pass downwardly through the ore while covered by the hood,and an igniter located within the hood for setting fire to the I ore atits surface.

44. In an apparatus for forming relatively thin cakes of agglomerated orsintered ore from a mass initially containing a metalbearing material inpulverized form and a combustible ingredient, the combination of Aanopen-top holder adapted to have disposed therein a relatively thin layerof the said mass and having` walls surrounding the said layer and aperforate bottom on which it rests, an air-supplying mechanism, a hoodhaving an open bottom adapted to be temporarily in air-tight connectionwith the said open top of the said holder, igniting means within thehood arranged to set iire to the combustible ingredients at the surfaceof the said mass, and means for tilting the holder to remove the sintercake formed therein from the walls which surround it.

45. ln an apparatus for forming relatively thin cakes of agglomerated orsintered'ore from a mass initially containing a metalbearing material inpulverized form and also 'a combustible ingredient, the combination ofa` box-like holder for a relatively thin layer of the said mass having aperforated bottom, arranged between an upper ore chamber and a lower gaschamber thereof, a superjacent air-hood with which the said oreholdercan have temporary gas-tight connection, the hood and holder beingseparable, means in the hood for causing ignition of the combustibleelement of the mass at the upper surface of the layer thereof, means forcausing combustion-supporting gas to move downwardly through the hood,through the region of i ition, and then through the ore layer, an a ductbelow the ore holder adapted to communicate with the gas chamber thereoffor carrying away the air and gases which pass through the ore mass intheholder.

46. vln an apparatus for forming relatively thin cakes of agglomeratedor sintered ore from a mass initially containing a metalbearing materialin' pulverized form and also a combustible ingredient, the combinationof a box-like holder for a relatively thin layer of the said mass havinga perforated bottom, arranged between an upper. ore chamber and a lowergas` chamber thereof, a super-jacent hood with which the said ore-holdercan have temporary gas-tight connection, the hood and holder beingseparable, means in the hood for causing ignition of the combustibleelement of the mass at the upper surface of the layer thereof, means forcausing combustion-supporting gas to move downwardly through the hood,"through the region of ignition, and then through the ore layer, a ductbelow the ore-holder adapted to communicate with the gas chamber thereoffor carrying away the air and gases which pass through the ore mass inthe holder, and means-for tilting the holder to discharge the sinteredore therefrom.

47. An igniter for use in ore sintering apparatus comprising anopen-bottom chamber located above a layer of ore the surface of which isto be ignited, and adapted to be filled with particles heated to anoreigniting temperature, the said chamber hav.y ing closed sidesarranged to confine and direct the hot materials therein.

48. In an apparatus for sintering ore, the combination of a holderhaving a pervious grate adapted to. support-a thin pervious layer ofore, an igniter comprising a chamber arranged above the surface lof theore,

and adapted to contain, confine and direct downwardly, hot ore-ignitingmaterials, a duct leading to the chamber through which may be supplied agaseous fluid for maintaining the supply of hot materials within thechamber, and means for causing air to be drawn down through the ore andits bed. whereby the heated contents of the said chamber are drawntherefrom into the body of ore.

49. In a ysintering apparatus, the combination of a support for a bodyof ore having a perviousl grate on which the ore is disposed in a thinpervious layer, an igniter for the ore comprising a chamber'y closed atits sides for confining hot materials for igniting the ore, and meansfor drawing air through the body of ore to induce and maintain internalcombustion in the mass thereof, the said chamber of the igniter beingopen to admit air thereto, whereby the gaseous contents thereof are`brought into contact with the ore to insure uniform igniting at thesurface thereof.

ln testimon whereof I aliix my signature in presence'o two witnesses.

JOHN E. GREENAWALT. Witnesses:

JNO. G. POWELL, F. E. BOWEN.

